This week's attention on the NSA's domestic surveillance has reminded me of an exchange from 2006 in which Gen. Michael Hayden, former head of the NSA, claimed that the Fourth Amendment doesn't require probable cause and, furthermore, "if there's any amendment to the Constitution that employees of the National Security Agency are familiar with, it's the Fourth."

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.